package core_sql.day01

/**
  * tranformation 转换
  * action    执行操作，能够触发job的操作
  *
  * Transformations
  * map(func)
  * filter(func)
  * flatMap(func)
  * mapPartitions(func)
  * mapPartitionsWithIndex(func)
  * sample(withRelacement,fraction,seed)
  * union(otherDataset)
  * intersection(otherDataset)     交集
  * distinct（[numTasks]）
  * groupByKey([numTask])
  * reduceByKey(func,[numTasks])
  * aggregateByKey(zeroValue)(seqOp,combOp,[numTasks])
  * sortByKey([ascending],[numTasks])
  * join(otherDataset,[unmTasks])
  * cogroup(otherDataset,[numTasks])
  *               When called on datasets of type (K, V) and (K, W),
  *               returns a dataset of (K, (Iterable<V>, Iterable<W>)) tuples.
  *               This operation is also called groupWith.
  *
  * cartesian(other Dataset)
  *       When called on datasets of types T and U, returns a dataset of (T, U) pairs (all pairs of elements).
  *
  * pipe(command,[envVars])
  *
  * coalesce(numPartitions)
  * repartition(numPartitions)
  * repartitionAndSortWithinPartitions(partitioner)
  *
  *
  * Actions:
  * reduce(func)
  * colect()
  * count()
  * first()
  * take(n)
  * takeSample(withReplacement,num,[seed])
  * takeOrdered(n,[ordering])
  * saveAsTextFile(path)
  * saveAsSequenceFile(path)
  * saveAsObjectFile(path)
  * countByKey()
  * foreach(func)
  *
  *
  *
  */
class Tranformation_Action {

}
